PostDescription

Also, since Post is a struct, the intializer is automatically created for you, so you don't even need to write your own init() method for it.

Hello Ciaran

Ok - the reason you're receiving an error, is because you're not initialising the constant 'tag' in your init method to accept a passed in value, you're assigning it a value in the init method.

Please take a look at the below example, which worked for me.

struct Tag {
    let name: String
}
struct Post {
    let title: String
    let author: String
    let tag: Tag
    init (title: String, author: String, tag: Tag) {
        self.title = title
        self.author = author
        self.tag = Tag(name: tag.name)
    }
    func description() -> String {
        let p1 = "\(title) by \(author). Filed under \(tag.name)"
        return p1

    }
}

let firstPost = Post(title: "iOSDevelopment", author: "Apple", tag: Tag(name: "Swift"))

let postDescription = firstPost.description()

So first take a look at the line

    init (title: String, author: String, tag: Tag)

I've told the init method to accept a another parameter, of type Tag.

Next -

self.tag = Tag(name: tag.name)

This tells the init method to set up 'tag' to accept the struct Tag.

let firstPost = Post(title: "iOSDevelopment", author: "Apple", tag: Tag(name: "Swift"))

You'll notice that in firstPost you have to type out the correct syntax for initialising the Tag struct, and you put "Swift" into the place of tag.name, which then allows you to create a full instance of Post.

I hope this helps. Please let me know if you don't understand what I've written.

Regards

Simon